N-teminal Telopeptides Of Type Ⅰcollagen In Gingival Crevicular Fluid And Periodontitis

Objectives: TypeⅠcollagen are widely distributed in the periodontal tissues, accounting for 80%-90% of the alveolar bone organic compounds, 80% of periodontal ligament collagen content, gingival connective tissue also contain large amounts of typeⅠcollagen.N-terminal Telopeptides of Type I collagen is one cross-linked product of typeⅠcollagen when it break down. N-terminal of typeⅠcollagen fibers are connected by pyridinoline or deoxypyridinoline and another 930 amino- acid of collagen molecules by the increased activity of osteoclasts or bone collagen degradation generated. In the bone resorption process, these fragments have been released, that is considered as a specific markers of bone resorption.Periodontitis is characterized by destruction in periodontal diseases. When periodontal disease occurres, gingival collagen fiber and alveolar bone structure destroy and lose attachment. NTX as typeⅠcollagen degradation products may be released into the gingival crevicular fluid (GCF) and closely relate to severity of periodontal disease or the integrity of periodontal supporting tissues. However, the research of NTX in GCF has not yet been reported.The aim of this study was to examine the NTX levels in GCF with ELISA test, assessed the relation between clinical parameters and NTX levels in subjects with healthy periodontia, gingivitis, and chronic periodontitis, then discussed NTX in the diagnosis of periodontitis value. Methods:1 Clinical dataForty-one subjects were selected from the stomatology department of Bethune International Peace hospital. They were categorized into four groups based on clinical examination, radiographic bone loss and diagnostic criteria of healthy periodontia, gingivitis, chronic non-active periodontitis group and chronic active periodontitis group.In periodontal healthy group maxillary first molar selected as subjects teeth. In gingivitis group and chronic periodontitis group the teeth with the most obvious clinical symptom was choosen as observation teeth. Each patient collected MB and DL two sites'gingival crevicular fluid. A total of forty-one GCF samples were collected.2 Methods of GCF collectionGingival crevicular fluid samples were collected using filter paper and weighing method that described by Lamster. Used Whatman 3 filter paper strips (2 mm×10 mm) which had been weighted, then inserted into teeth's MB and DL two sites. Removed the filter paper after 30 second into the Eppendorf tube re-weighing. Stored in -20℃for preservation, waiting for test.3 Clinical parameter including gingival index, the greatest probing depth and attachment loss level were examined and recorded.4 Used commercial NTX ELISA Kit to measure the concentration of NTX in GCF.Results:1 The comparison of GCF volumes among healthy periodontia, gingivitis, chronic non-active periodontitis groups and chronic active periodontitis groups:The GCF volume of healthy periodontia group was 1.04±0.375μl, the GCF volume of gingivitis group was 1.06±0.390μl, the GCF volume of chronic non-active periodontitis group was 1.32±0.432μl, the GCF volume of chronic active periodontitis group was 1.80±0.268μl. There was a statistically significant difference among the four groups(P<0.05). The LSD-t Test was performed, the results showed that the differences were statistically significant between chronic active periodontitis group and the other three groups (P<0.05). However, the comparison among the healthy periodontia, gingivitis and chronic non-active periodontitis did not reach a statistically significant level (P>0.05).2 The comparison of NTX concentration among healthy periodontia, gingivitis and chronic non-active periodontitis groups and chronic active periodontitis groups:The NTX concentration of healthy periodontia group was 2.27±0.373nmol/L, the NTX concentration of gingivitis group was 2.50±0.398nmol/L, the NTX concentration of chronic non-active periodontitis group was 2.73±0.582nmol/L, the NTX concentration of chronic active periodontitis group was 3.30±0.895nmol/L, and its measured values of the 95% confidence interval was (2.608, 3.983) nmol/L. There was a statistically significant difference among the four groups(P<0.05).The LSD-t Test was performed, the results showed that the differences were statistically significant between chronic active periodontitis group and the other three groups (P<0.05). However, the comparison among the healthy periodontia, gingivitis and chronic non-active periodontitis did not reach a statistically significant level (P>0.05).3 The correlation coefficients between the NTX concentration and clinical parameters were 0.420, 0.519, 0.421(P<0.05). There were significant positive correlations between the NTX amount and clinical parameters.Conclusions:1 GCF volume increased from healthy to periodontitis sites. Chronic active periodontitis group was statistically significant different from the other three groups. The data indicated that GCF volume changes reflected that in the extent of periodontal disease.2 NTX concentration increased in GCF from healthy to periodontitis sites.The data indicated that GCF NTX concentration changes were closely related to the development of periodontal disease. Chronic periodontitis groups was statistically significant different from the other three groups. Therefore, levels of NTX in GCF might become evaluation of periodontal disease, periodontal tissue inflammation and damage as an important reference index.3 There were positive correlations between GCF NTX amount and clinical parameters, but according to statistical theory, the values of R2 were very low and need for further research.4 The measurement method of NTX levels in gingival crevicular fluid is simple, it could be more accurately reflect the change than clinical periodontal index in periodontal diseases. It provideds a new diagnosis index in periodontal disease.